wEll, indeed, they're a business, and there is always a tension between being good and looking good. Many British firms would rather spend money on PR than improvement.
I'm not one of these who get very upset about shipping food, international trade is a good thing, so I don't see Mackies as bad people for this.
Actually it's a very good thing, and unless you do mad stuff like air freighting potatoes, the energy consumption of ships is really small.
Oh yes to the list of marekting buzzwords (organic, natural, scientific) et al, we have to add "local". People like "local".
Waitrose, who aren't the worst supermarket, recently had posters up saying something like "local growers all over the world", for their producers, to exploit that view.
Saldy we are lurching into a time when people will lurch into behaviours that they think they can understand, rather than do any good.
Transport seems to be taking that on the chin big time. Some is wasteful of course but the really big impacts are from stuff that greens don't lobby about because they're not very interesting.
Greens like "empowerment", and "building awareness", so retail fits that quite well.
Those wish to keep western farmers rich, at the cost of keeping 3rd world farmers poor like this trend towards local and "organic". Organic is a fine trade barrier. You won't get hassles from international bodies, since it's not a government barrier, and it allows western farmers to charge more. Peasant farmers simply can't afford the bureaucracy for this, so are excluded from competition. However the big landowners in the 3rd world may do so, and of course they can be negotiated with to act "responsibly", this is defined as "not undercutting western farmers".